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Tropical Medicine and Infectious Disease Nov 2022Intestinal parasitic infections are common infectious diseases causing many health problems and impaired growth and physical development.. Children under five years old... (Review)
Review
Intestinal parasitic infections are common infectious diseases causing many health problems and impaired growth and physical development.. Children under five years old are the most vulnerable to infections, due to their immature immunity and feeding and exploratory behaviours. This systematic review aimed to assess the relationship between intestinal parasitic infections and undernutrition among children under 5 years old. Fifteen studies met the inclusion and exclusion criteria and were classified as high-quality studies. Twelve parasites were reported, including , spp., , , , hookworm, , , spp. and . Ascariasis is the most reported infection, with a prevalence ranging from 10.77% in Ethiopia to 57.14% in Malaysia, and is correlated with stunting (OR 2.17 (95% CI 1.14, 4.13), = 0.02). Giardiasis is the second most reported infection, with a prevalence ranging from 4.43% in Ethiopia to 66.33% in the Central African Republic, and is related to an increased risk of stunting (OR 2.34 (95% CI 1.07, 5.10), = 0.03)), wasting (OR 2.90 (95% CI 1.12, 7.49, = 0.03)), and being underweight (OR 1.53 (95% CI 1.02, 2.29, = 0.04)). The third and fourth most prevalent infections are and hookworm infections. Intestinal parasitic infections can occur very early in life and cause significant growth retardation. It is important to understand the prevalence and effects of infection based on the parasite species in order to implement therapeutic interventions and prevention controls.
PubMed: 36422922
DOI: 10.3390/tropicalmed7110371 -
Microbial Pathogenesis Feb 2020There are numerous epidemiological and experimental evidences to suggest that Ascaris lumbricoides infection is a neglected risk factor for development of asthma. For... (Review)
Review
There are numerous epidemiological and experimental evidences to suggest that Ascaris lumbricoides infection is a neglected risk factor for development of asthma. For this purpose, we conducted a systematic review and meta-analysis for better understanding of this relationship. Systematic searching (PubMed, Scopus, Web of Science and Google Scholar) was done, up to September 30, 2019 to identify the relevant studies. We applied random-effects meta-analysis model to generate the overall odds ratio (OR) and 95% confidence intervals (CIs). Heterogeneity was assessed with I and τ statistic. Finally, 19 studies (totally 25 datasets), including 14 datasets with microscopic methods (1830 asthmatic patients (APs) and 3802 healthy controls (HCs)) and 11 datasets with serological methods (1543 APs and 3507 HCs) met the eligibility criteria. Considering to the serological methods, our results demonstrated that the APs had higher seroprevalence rate of A. lumbricoides (48.3% vs. 35.1%) than HCs, showing a significant association (pooled crude OR, 1.53; 95%CI, 1.07-2.18). Moreover, microscopic methods showed a higher prevalence of A. lumbricoides infection in the APs compared to the HCs (37.2% vs. 30.2%), but no significant association was found between APs and HCs (pooled crude OR, 1.19; 95%CI, 0.92-1.55). After adjustment for confounders, results showed no significant association for both serological (pooled adjusted OR, 1.43; 95%CI, 0.93-2.19) and microscopic (pooled adjusted OR, 1.05; 95%CI, 0.78-1.42) methods. Despite heterogeneous results, accurate and better quality studies are needed to determine the effect of A. lumbricoides infection on induction or exacerbation of asthma.
PubMed: 32101769
DOI: 10.1016/j.micpath.2020.104099 -
Transactions of the Royal Society of... Nov 2023The aberrant migration of Ascaris lumbricoides may cause extra-intestinal ascariasis (EIA) involving hepato-biliary-pancreatic (HBP) or other extra-gastro-intestinal... (Meta-Analysis)
Meta-Analysis
The aberrant migration of Ascaris lumbricoides may cause extra-intestinal ascariasis (EIA) involving hepato-biliary-pancreatic (HBP) or other extra-gastro-intestinal (EGI) organs. We performed a systematic review and meta-analysis to study the risk factors and clinical presentations of EIA, and differences in HBP and EGI ascariasis. Medline, Web of Science and Embase were searched for cases of EIA in the English language from India. From 1204 articles, 86 studies (105 cases) were included. The majority of the cases involved the HBP system (78%). Among HBP ascariasis, the most commonly involved site was the bile duct (53.6%). Females had 11.3 times higher odds (95% CI 2.852 to 44.856; p=0.001) of HBP ascariasis, while the pediatric population had lower odds (OR=0.323). Previous gallbladder disease was significantly associated with HBP ascariasis in adults (p=0.046), while a significantly higher number of cases of EGI ascariasis were observed among pediatric patients (p=0.003). Ocular symptoms occurred exclusively in the pediatric population (p=0.017). Overall, death was reported in 3.8% of patients (n=4). This review emphasizes the importance of the complications of EIA. It encourages future research into issues such as the reasons of higher gall bladder ascariasis in females and the implications of Ascaris-related complications following biliary tract interventions. It also suggests considering Ascaris as a differential diagnosis for airway obstuction in intubated critically ill patients.
Topics: Adult; Animals; Female; Child; Humans; Ascariasis; Ascaris lumbricoides; Intestines; Gastrointestinal Tract; India
PubMed: 37264906
DOI: 10.1093/trstmh/trad033 -
Acta Tropica Mar 2023It has been tested and proven that vaccination is still the best strategy to combat infectious diseases. However, to date, there are still no vaccines against human... (Review)
Review
It has been tested and proven that vaccination is still the best strategy to combat infectious diseases. However, to date, there are still no vaccines against human soil-transmitted helminthic diseases, despite their high prevalence globally, particularly in developing countries and rural areas with tropical climates and poor sanitation. The development of vaccines against helminths is riddled with obstacles. Helminths have a complex life cycle, multiple stages within the same host with stage-specific antigen expression, and the ability to regulate host immune reactions to evade the immune response. These elements contribute to the main challenge of helminthic vaccines: the identification of effective vaccine candidates. Therefore, this article reviews the current progress and potential future direction of soil-transmitted helminthic vaccines, particularly against Trichuris trichiura, Ascaris lumbricoides, Strongyloides stercoralis, Necator americanus and Ancylostoma duodenale. The study design employed was a systematic review, using qualitative meta-summary synthesis. Preclinical studies and clinical trials on the development of protein subunit vaccines against the five soil-transmitted helminths were searched on PubMed and Scopus. Effectiveness was indicated by a reduction in worm burden or larval output, an increase in specific IgG levels, or an increase in cytokine production. Our findings show that only the hookworm vaccine against N. americanus is in the clinical trial phase, while the rest is still in exploratory research and pre-clinical development phase.
Topics: Animals; Humans; Soil; Hookworm Infections; Ascaris lumbricoides; Ancylostomatoidea; Necator americanus; Vaccines; Helminthiasis; Feces
PubMed: 36586174
DOI: 10.1016/j.actatropica.2022.106796 -
Allergy Apr 2011The rate of increase in prevalence of allergic disease in some countries implies environmental exposures may be important etiological factors. Our aim was to undertake a... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
The rate of increase in prevalence of allergic disease in some countries implies environmental exposures may be important etiological factors. Our aim was to undertake a systematic review and meta-analysis of epidemiological studies to quantify the association between current intestinal parasite infection and the presence of atopy and to determine whether this relation is species specific.
METHODS
We searched MEDLINE, EMBASE, LILIACS and CAB Abstracts (to March 2009); reviews; and reference lists from publications. No language restrictions were applied. We included studies that measured current parasite infection using direct fecal microscopy and defined atopy as allergen skin sensitization or presence of specific IgE. We estimated pooled odds ratios (OR) and 95% confidence intervals (95% CI) using data extracted from published papers using random-effects model.
RESULTS
Twenty-one studies met our inclusion criteria. Current parasite infection was associated with a reduced risk of allergen skin sensitization OR 0.69 (95% CI 0.60-0.79; P < 0.01). When we restricted our analyses to current geohelminth infection, the size of effect remained similar OR 0.68 (95% CI 0.60-0.76; P < 0.01). In species-specific analysis, a consistent protective effect was found for infection with Ascaris lumbricoides, Tricuris trichuria, hookworm and Schistosomiasis. There were insufficient data to pool results for atopy defined by the presence of specific IgE.
CONCLUSION
Intestinal parasite infection appears to protect against allergic sensitization. Work should continue to identify the mechanisms of this effect and means of harnessing these to reduce the global burden of allergic disease.
Topics: Dermatitis, Atopic; Humans; Intestinal Diseases, Parasitic
PubMed: 21087217
DOI: 10.1111/j.1398-9995.2010.02512.x -
PLoS Medicine Mar 2014Preventive chemotherapy represents a powerful but short-term control strategy for soil-transmitted helminthiasis. Since humans are often re-infected rapidly, long-term... (Meta-Analysis)
Meta-Analysis Review
BACKGROUND
Preventive chemotherapy represents a powerful but short-term control strategy for soil-transmitted helminthiasis. Since humans are often re-infected rapidly, long-term solutions require improvements in water, sanitation, and hygiene (WASH). The purpose of this study was to quantitatively summarize the relationship between WASH access or practices and soil-transmitted helminth (STH) infection.
METHODS AND FINDINGS
We conducted a systematic review and meta-analysis to examine the associations of improved WASH on infection with STH (Ascaris lumbricoides, Trichuris trichiura, hookworm [Ancylostoma duodenale and Necator americanus], and Strongyloides stercoralis). PubMed, Embase, Web of Science, and LILACS were searched from inception to October 28, 2013 with no language restrictions. Studies were eligible for inclusion if they provided an estimate for the effect of WASH access or practices on STH infection. We assessed the quality of published studies with the Grades of Recommendation, Assessment, Development and Evaluation (GRADE) approach. A total of 94 studies met our eligibility criteria; five were randomized controlled trials, whilst most others were cross-sectional studies. We used random-effects meta-analyses and analyzed only adjusted estimates to help account for heterogeneity and potential confounding respectively. Use of treated water was associated with lower odds of STH infection (odds ratio [OR] 0.46, 95% CI 0.36-0.60). Piped water access was associated with lower odds of A. lumbricoides (OR 0.40, 95% CI 0.39-0.41) and T. trichiura infection (OR 0.57, 95% CI 0.45-0.72), but not any STH infection (OR 0.93, 95% CI 0.28-3.11). Access to sanitation was associated with decreased likelihood of infection with any STH (OR 0.66, 95% CI 0.57-0.76), T. trichiura (OR 0.61, 95% CI 0.50-0.74), and A. lumbricoides (OR 0.62, 95% CI 0.44-0.88), but not with hookworm infection (OR 0.80, 95% CI 0.61-1.06). Wearing shoes was associated with reduced odds of hookworm infection (OR 0.29, 95% CI 0.18-0.47) and infection with any STH (OR 0.30, 95% CI 0.11-0.83). Handwashing, both before eating (OR 0.38, 95% CI 0.26-0.55) and after defecating (OR 0.45, 95% CI 0.35-0.58), was associated with lower odds of A. lumbricoides infection. Soap use or availability was significantly associated with lower infection with any STH (OR 0.53, 95% CI 0.29-0.98), as was handwashing after defecation (OR 0.47, 95% CI 0.24-0.90). Observational evidence constituted the majority of included literature, which limits any attempt to make causal inferences. Due to underlying heterogeneity across observational studies, the meta-analysis results reflect an average of many potentially distinct effects, not an average of one specific exposure-outcome relationship.
CONCLUSIONS
WASH access and practices are generally associated with reduced odds of STH infection. Pooled estimates from all meta-analyses, except for two, indicated at least a 33% reduction in odds of infection associated with individual WASH practices or access. Although most WASH interventions for STH have focused on sanitation, access to water and hygiene also appear to significantly reduce odds of infection. Overall quality of evidence was low due to the preponderance of observational studies, though recent randomized controlled trials have further underscored the benefit of handwashing interventions. Limited use of the Joint Monitoring Program's standardized water and sanitation definitions in the literature restricted efforts to generalize across studies. While further research is warranted to determine the magnitude of benefit from WASH interventions for STH control, these results call for multi-sectoral, integrated intervention packages that are tailored to social-ecological contexts.
Topics: Adolescent; Adult; Animals; Child; Child, Preschool; Hand Disinfection; Humans; Hygiene; Infant; Infant, Newborn; Nematoda; Nematode Infections; Sanitation; Soil
PubMed: 24667810
DOI: 10.1371/journal.pmed.1001620 -
The Journal of Allergy and Clinical... Jun 2022There is considerable research interest in the role of helminth infections in the development of allergic diseases. However, findings from previous studies are mixed.... (Meta-Analysis)
Meta-Analysis
BACKGROUND
There is considerable research interest in the role of helminth infections in the development of allergic diseases. However, findings from previous studies are mixed. Existing systematic reviews of these studies are outdated. We performed a systematic review of the global literature on the association between helminth infections and development and clinical outcomes of allergic diseases.
METHODS
We searched Cochrane Library, MEDLINE, EMBASE, ISI Web of Science, PubMed, Global Index Medicus, Scielo, KoreaMed, Google Scholar, and Lilacs for studies published up to January 2020. We included observational epidemiological studies (cohort, case-control, and cross-sectional studies) of children and adults reporting associations between helminth infections and asthma, allergic rhinitis, eczema, and atopy. We performed random-effects meta-analysis to summarize the effect estimates.
RESULTS
We included 80 studies with 99,967 participants. In the meta-analyses, we did not observe an overall association between helminth infections and allergic diseases. There was, however, evidence that Ascaris lumbricoides infections were associated with an increased risk of bronchial hyperreactivity in children (risk ratio, 1.41; 95% CI, 1.17-1.70; I = 50; P for I = .09), and were associated with an increased risk of atopy among helminth-infected adults (risk ratio, 1.37; 95% CI, 1.18-1.61; I = 52; P for I = .02). We found no study that addressed the association between helminth infection and clinical outcomes of allergic diseases. The overall strength of the underlying evidence was low to moderate.
CONCLUSIONS
Helminth infections may increase the risk of bronchial hyperreactivity in children and atopy in adults. Well-designed longitudinal cohorts may help clarify potential causal associations between chronic helminth infections and allergic diseases.
Topics: Adult; Animals; Bronchial Hyperreactivity; Child; Cross-Sectional Studies; Helminthiasis; Helminths; Humans; Hypersensitivity, Immediate; Rhinitis, Allergic
PubMed: 34968529
DOI: 10.1016/j.jaci.2021.12.777 -
American Journal of Respiratory and... Sep 2006Epidemiologic studies suggest that intestinal parasite infections may protect against asthma. (Meta-Analysis)
Meta-Analysis Review
RATIONALE
Epidemiologic studies suggest that intestinal parasite infections may protect against asthma.
OBJECTIVES
A systematic review and meta-analysis of epidemiologic studies to determine whether total or species-specific current parasite infection is associated with a reduced risk of asthma or wheeze.
METHODS
We searched MEDLINE, EMBASE, and CINAHL (up to January 2006); reviews; and reference lists from publications, with no language restrictions. We included studies that reported asthma or wheeze as an outcome measure and ascertained parasite infection by fecal examination. We estimated pooled odds ratios (OR) and 95% confidence intervals (CI) using data extracted from published papers, or where available, original data provided by authors, using random effect models.
MEASUREMENTS AND MAIN RESULTS
Thirty-three studies met the inclusion criteria. Infection with any parasite was associated with a small, nonsignificant increase in asthma risk (OR, 1.24; 95% CI, 0.98-1.57; 29 studies). In species-specific analysis, Ascaris lumbricoides was associated with significantly increased odds of asthma (OR, 1.34; 95% CI, 1.05-1.71; 20 studies), while hookworm infection was associated with a significantly strong reduction (OR, 0.50; 95% CI, 0.28-0.90; 9 studies) that was directly and significantly related to infection intensity (p < 0.001; OR for highest tertile of infection, 0.34; 95% CI, 0.19-0.62). Other species had no significant effects on asthma. Infection effects on wheeze were derived from smaller numbers, but revealed a broadly similar pattern of results.
CONCLUSIONS
Parasite infections do not in general protect against asthma, but infection with hookworm may reduce the risk of this disease.
Topics: Adult; Asthma; Child; Humans; Intestinal Diseases, Parasitic; Risk Assessment
PubMed: 16778161
DOI: 10.1164/rccm.200603-331OC -
Infectious Diseases of Poverty Jul 2018Soil transmitted helminth (STH) infections still remain a notable health problem in resource-limited countries due to difficulties in the implementation of control... (Review)
Review
BACKGROUND
Soil transmitted helminth (STH) infections still remain a notable health problem in resource-limited countries due to difficulties in the implementation of control measures. In Nigeria for instance, despite several community-based and provincial reports, national data on prevalence, burdens and risk zones (RZs) for STH infections are lacking.
METHODS
The present study employed the recommendations of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) to determine the prevalence, distribution and RZs for STH infections among Nigerian children through a meta-analysis of data published between 1980 and 2015. Pooled prevalence estimate (PPE) was determined by the random-effects model while heterogeneity was evaluated using the Cochran's Q-test.
RESULTS
A total of 18 901 of the 34 518 Nigerian children aged 0-17 years examined across 19 Nigerian states during the period under review were infected with one or more species of STHs. The overall PPE for STH infections was 54.8% (95% CI: 54.2-55.3). PPEs for sub-groups ranged between 13.2% (95% CI: 11.5-15.1) and 80.9% (95% CI: 80.0-81.7). Highest PPEs for STH infections were observed among children within community settings (59.0%, 95% CI: 57.7-60.4) and school-aged children (54.9%, 95% CI: 54.3-55.5). Ascaris lumbricoides was the most prevalent species (44.6%, 95% CI: 44.0-45.2). Over 36% (15/41) of the studies were published from south-western Nigeria. South-western region was the only high risk zone (HRZ) for STH infections while the rest of the regions were low risk zones (LRZs).
CONCLUSIONS
STH infections involving Ascaris lumbricoides, Strongyloides stercoralis, Trichuris trichiura and hookworms are highly prevalent across Nigeria. Strategic use of anthelmintics, health education and adequate sanitation, taking into account this epidemiologic information will help in the control of these infections in Nigeria.
Topics: Animals; Child Health; Helminthiasis; Helminths; Humans; Nigeria; Prevalence; Soil
PubMed: 29983115
DOI: 10.1186/s40249-018-0451-2 -
Parasitology Research Jan 2022Trichuriasis is one of the most common soil-transmitted helminth (STH) infections, affecting populations globally. The condition is particularly prevalent in tropical... (Meta-Analysis)
Meta-Analysis Review
Trichuriasis is one of the most common soil-transmitted helminth (STH) infections, affecting populations globally. The condition is particularly prevalent in tropical and subtropical areas with low levels of sanitation and poor living conditions. The objective of this systematic review and meta-analysis was to evaluate the prevalence of Trichuris trichiura infection in Asia at the country and region level. Multiple databases/academic search engines (Web of Science, PubMed, ProQuest, Scopus, and Google Scholar) were searched for literature on T. trichiura prevalence in Asia published through January 2021. Pooled prevalence was determined using the meta-package in R (version 3.6.1). Out of 13,836 articles, 226 studies (5,439,500 individuals) from 26 countries met the inclusion criteria. Of the 226 studies, 151 were community-based studies that included individuals across the age spectrum, while 75 studies focused on school children (typically in the 5-16 years age range). The overall T. trichiura pooled prevalence was 15.3% (95% CI: 12.4-19.1%), with a pooled prevalence of 13.3% (95% CI: 10.0-17.1%) for the community studies and 20.9% (95% CI: 14.7-27.9%) for the studies only including school children. For studies including all age groups, individuals in the 1-15 years age group had the highest pooled prevalence at 23.4% (95% CI: 1.7-49.4%). There was a significant difference found in overall pooled prevalence by sex (p < 0.001) and community type (rural versus urban) (p < 0.001). Although prevalence appears to be decreasing, study findings suggest that T. trichiura infection continues to be a public health problem in Asia. Therefore, control programs focused on at-risk individuals in endemic areas are needed.
Topics: Adolescent; Animals; Ascariasis; Ascaris lumbricoides; Asia; Child; Child, Preschool; Feces; Helminthiasis; Humans; Infant; Prevalence; Sanitation; Soil; Trichuriasis; Trichuris
PubMed: 34993634
DOI: 10.1007/s00436-021-07365-8